Methods and apparatus for operating an inkjet printing system

Abstract

The invention provides a method of operating a inkjet printing system that may include a print head parking structure and a print head cleaning station. A print head parking structure may include a solvent and/or nozzle surface treatment bath for inkjet print heads. Print heads may be returned to the print head parking structure after a substrate has been printed, after one or more printing passes, and/or frequently enough to prevent ink from drying on or clogging the print heads. Once sealed within the print head parking structure, the print heads (or a portion thereof) may be dipped in a solvent bath to dissolve or wash away any ink that has been deposited on the print heads. The print heads may be coated with a surface treatment that improves jetting reliability. The print heads may be dried and moved to the print head cleaning station where they may be wiped and pre-jetting may be performed.

1 . A method of operating an inkjet printing system for manufacturing color filters for flat panel displays, comprising: 
 processing a print head in a parking structure;    processing the print head in a cleaning station;    pre-jetting the print head in the cleaning station; and    printing a color filter.    
     
     
         2 . The method of  claim 1  wherein processing the print head in the parking structure includes: 
 sealing nozzles of the print head in the parking structure; and    dipping the nozzles in a solvent in a pool.    
     
     
         3 . The method of  claim 2  wherein processing the print head in the parking structure further includes: 
 spraying the print heads with solvent emitted by spray nozzles positioned in the pool of solvent.    
     
     
         4 . The method of  claim 2  wherein processing the print head in the parking structure further includes: 
 purging the print head into the pool.    
     
     
         5 . The method of  claim 2  wherein processing the print head in the parking structure further includes: 
 draining used solvent from the solvent pool.    
     
     
         6 . The method of  claim 5  wherein processing the print head in the parking structure further includes: 
 refilling the solvent pool with new solvent.    
     
     
         7 . The method of  claim 5  wherein processing the print head in the parking structure further includes: 
 filling the solvent pool with a surface treatment solution.    
     
     
         8 . The method of  claim 7  wherein processing the print head in the parking structure further includes: 
 dipping the nozzles in the surface treatment solution.    
     
     
         9 . The method of  claim 8  wherein the surface treatment solution includes a mixture of alkyl thiol and ionic alkyl thiol dissolved in a solvent.  
     
     
         10 . The method of  claim 2  wherein processing the print head in the parking structure further includes: 
 drying the print head.    
     
     
         11 . The method of  claim 10  wherein the drying the print head is achieved through the use of clean dry air.  
     
     
         12 . The method of  claim 1  wherein processing the print head in the cleaning station further includes: 
 wiping the print head with a cleaning medium.    
     
     
         13 . The method of  claim 1  wherein the parking station is coupled to a moving platform adapted to position the parking station directly under the print head.  
     
     
         14 . A system for inkjet printing color filters for flat panel displays comprising: 
 a print head mounted on a bridge and adapted to be moved between a printing location, a parking location, and a cleaning location;    a parking structure disposed at the parking location; and    a cleaning station disposed at the cleaning location.    
     
     
         15 . The system of  claim 14  wherein the system is operative to: 
 process the print head in the parking structure;    process the print head in the cleaning station;    pre-jet the print head in the cleaning station; and    print a color filter.    
     
     
         16 . The system of  claim 14  wherein the parking structure further includes a solvent pool in which nozzles of the print head are dipped.  
     
     
         17 . The system of  claim 14  wherein the parking structure further includes a solvent pool including at least one spray nozzle for spraying the print head with solvent.  
     
     
         18 . The system of  claim 14  wherein the parking structure further includes a pool of surface treatment solution in which nozzles of the print head are dipped.  
     
     
         19 . The system of  claim 18 , wherein the surface treatment solution includes hydrophobic materials.  
     
     
         20 . The system of  claim 18 , wherein the surface treatment solution includes inkphobic materials.  
     
     
         21 . The system of  claim 18  wherein the surface treatment solution includes a mixture of alkyl thiol and ionic alkyl thiol dissolved in a solvent.  
     
     
         22 . The system of  claim 14 , wherein the parking station further includes clean dry air for drying the print head.  
     
     
         23 . The system of  claim 14 , wherein the cleaning station further includes a cleaning medium adapted to wipe the print head.